For some 20 years now, optical liquid crystals have fundamentally changed display technology. As economically priced light valves, they are also often used in the switching of the optical flow of information. The development of ferroelectric liquid crystals has moved switching times into the microsecond range. However, the fact that most of a liquid crystal's physical parameters are highly temperature dependent is still causing problems. Many technical instruments require that the components exhibit the same properties within a broad temperature range. In vehicle construction, in particular, temperature requirements are from −30° C. through +80° C. Optical overload-protection switches in open-air video-monitoring systems can also be exposed to such temperatures.
Examples of other applications are birefringent interference filters, which are spectrally tuned with the aid of liquid crystals (C. BARTA, et al., Crystal Optical Interference Filter, European Patent 0 907 089 A2).
So-called optically or electrically addressable, spatially resolving liquid crystal modulators (OASLM, EASLM), used to convert incoherent image information into coherent image information, were only able to be operated in conventional methods heretofore within narrow temperature ranges, since their switching times vary considerably in response to temperature.